Conventionally, desired pictures may be difficult to take due to constraints of equipment or operation modes. For example, to take pictures of a blooming and fading process of a flower, multiple pictures may need to be taken at certain times, and a status of the flower during anthesis, florescence, and fading may also vary. As a result, desired pictures may be missed due to a long shooting interval, and undesired pictures with inconspicuous or no change may be taken due to a short shooting interval.